Nanogap devices comprise pairs of electrodes with nanoscale spatial separation, which are capable of accommodating nano-objects, such as functionalized nanoparticles, nanowires and isolated molecules or molecular aggregates for electrical characterization and sensing applications.
Fabrication of nanogap devices has been of major interest, due to their promising application in nanotechnology. While nanogap devices have been utilized to electronically characterize nano-objects and molecules under a dry environment, studies conducted in aqueous solutions were limited by signal to noise issues. Electrical signal to noise ratios suffered from conduction through electrolyte solutions, where ionic currents are often many orders of magnitude greater than the current flowing through the object in the gap.
Measuring molecules and nano-sized materials electronically in a fluidic solution, however, is highly applicable for biological and chemical sensing, for nanoparticle detection and characterization and for catalysis and synthesis. Such devices can also find applications as switching and computing components in future electronic devices.
Devices and methods are needed that can accurately electronically probe nanostructures and molecules in solution. Such devices should allow for the detection of an electrical signal, which is not perturbed by background signals from the solution.